/* ============================================================================
   Get Recommended by AI - design system
   Palette is taken from the printed cover, so the site and the book are one
   object. Gold appears ONLY on the bestseller credential. The cyan-to-blue
   gradient appears ONLY on the word "AI" and on a selected answer row.
   ========================================================================== */

:root{
  --ink:#05070A;          /* cover black, page ground */
  --ink-2:#0A0F16;        /* lifted ground, alternating sections */
  --panel:#0E141C;        /* the answer card */
  --line:#1B2430;         /* hairlines */
  --line-2:#283542;       /* hairlines, brighter */
  --paper:#E8EDF4;        /* body text */
  --paper-hi:#FFFFFF;     /* headings */
  --mute:#8494A8;         /* secondary text */
  --mute-2:#6A7D93;       /* tertiary, captions. 4.77:1 on --ink, 4.55:1 on --ink-2 */
  --cy:#22D3EE;
  --blue:#3B82F6;
  --gold:#F5B942;
  --grad:linear-gradient(96deg,var(--cy) 0%,var(--blue) 100%);

  --display:"Archivo","Helvetica Neue",Arial,sans-serif;
  --body:"Newsreader",Georgia,"Times New Roman",serif;
  --mono:"IBM Plex Mono",ui-monospace,SFMono-Regular,Menlo,monospace;

  --wrap:1120px;
  --measure:34em;
  --r:14px;
}

*,*::before,*::after{box-sizing:border-box}

html{-webkit-text-size-adjust:100%}

body{
  margin:0;
  background:var(--ink);
  color:var(--paper);
  font-family:var(--body);
  font-size:1.0625rem;
  line-height:1.75;
  font-synthesis-weight:none;
  -webkit-font-smoothing:antialiased;
}

img{max-width:100%;height:auto;display:block}

a{color:var(--cy);text-underline-offset:.18em;text-decoration-thickness:from-font}
a:hover{color:var(--paper-hi)}

:focus-visible{outline:2px solid var(--cy);outline-offset:3px;border-radius:4px}

/* ---------- type ---------------------------------------------------------- */

h1,h2,h3,h4{
  font-family:var(--display);
  color:var(--paper-hi);
  font-weight:800;
  letter-spacing:-.025em;
  line-height:1.08;
  margin:0 0 .5em;
  text-wrap:balance;
}
h1{font-size:clamp(2.6rem,7.2vw,4.6rem);font-weight:900;letter-spacing:-.035em}
h2{font-size:clamp(1.75rem,3.6vw,2.6rem)}
h3{font-size:clamp(1.15rem,2vw,1.4rem);letter-spacing:-.015em}
h4{font-size:1.02rem;letter-spacing:-.005em}

p{margin:0 0 1.15em;max-width:var(--measure)}
.lede{font-size:clamp(1.1rem,1.9vw,1.3rem);line-height:1.62;color:var(--paper)}

strong{font-weight:600;color:var(--paper-hi)}

/* the one gradient, reserved for "AI" */
.ai{
  background:var(--grad);
  -webkit-background-clip:text;background-clip:text;
  color:transparent;
}

/* eyebrow / instrument labels */
.eyebrow{
  font-family:var(--mono);
  font-size:.7rem;
  letter-spacing:.16em;
  text-transform:uppercase;
  color:var(--mute-2);
  margin:0 0 1.1rem;
  display:block;
}

.num{font-family:var(--mono);font-variant-numeric:tabular-nums;letter-spacing:-.02em}

/* ---------- layout -------------------------------------------------------- */

.wrap{max-width:var(--wrap);margin:0 auto;padding:0 24px}
.narrow{max-width:720px;margin:0 auto;padding:0 24px}

section{padding:clamp(56px,8vw,104px) 0}
section.lift{background:var(--ink-2);border-block:1px solid var(--line)}

.rule{height:1px;background:var(--line);border:0;margin:0}

/* ---------- header -------------------------------------------------------- */

.site-head{
  position:sticky;top:0;z-index:50;
  background:rgba(5,7,10,.86);
  backdrop-filter:blur(14px);
  border-bottom:1px solid var(--line);
}
.site-head .wrap{display:flex;align-items:center;gap:28px;height:64px}
.brand{
  font-family:var(--display);font-weight:900;font-size:.95rem;
  letter-spacing:-.02em;text-transform:uppercase;color:var(--paper-hi);
  text-decoration:none;flex:none;
}
.brand:hover{color:var(--paper-hi)}
.site-nav{margin-left:auto;display:flex;gap:22px;align-items:center}
.site-nav a{
  font-family:var(--mono);font-size:.76rem;letter-spacing:.06em;
  text-transform:uppercase;color:var(--mute);text-decoration:none;
}
.site-nav a:hover,.site-nav a[aria-current=page]{color:var(--paper-hi)}
.nav-toggle{display:none}

@media(max-width:860px){
  .site-nav{
    position:absolute;top:64px;left:0;right:0;
    flex-direction:column;align-items:flex-start;gap:0;
    background:var(--ink);border-bottom:1px solid var(--line);
    padding:8px 24px 18px;
  }
  .site-nav a{padding:11px 0;width:100%}
  .site-nav[hidden]{display:none}
  .nav-toggle{
    display:block;margin-left:auto;background:none;border:1px solid var(--line-2);
    color:var(--paper);border-radius:8px;padding:7px 12px;font-family:var(--mono);
    font-size:.72rem;letter-spacing:.1em;text-transform:uppercase;cursor:pointer;
  }
}

/* ---------- buttons ------------------------------------------------------- */

.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:.5em;
  font-family:var(--display);font-weight:700;font-size:.95rem;letter-spacing:-.01em;
  padding:14px 22px;border-radius:10px;text-decoration:none;cursor:pointer;
  border:1px solid transparent;transition:transform .12s ease,background .15s ease;
}
.btn:active{transform:translateY(1px)}
.btn-primary{background:var(--paper-hi);color:var(--ink)}
.btn-primary:hover{background:#fff;color:var(--ink)}
.btn-ghost{background:transparent;border-color:var(--line-2);color:var(--paper)}
.btn-ghost:hover{background:rgba(255,255,255,.06);color:var(--paper-hi)}
.btn-row{display:flex;flex-wrap:wrap;gap:10px;margin:0 0 14px}
.btn small{font-family:var(--mono);font-weight:400;font-size:.72rem;color:inherit;opacity:.62}

/* ---------- bestseller credential (the only gold) ------------------------- */

.credential{
  display:inline-flex;align-items:center;gap:.6em;
  font-family:var(--mono);font-size:.74rem;letter-spacing:.08em;text-transform:uppercase;
  color:var(--gold);border:1px solid rgba(245,185,66,.34);
  background:rgba(245,185,66,.07);border-radius:999px;padding:6px 14px;
  margin:0 0 22px;
}
.credential svg{flex:none}

/* ---------- hero ---------------------------------------------------------- */

.hero{
  padding:clamp(44px,7vw,84px) 0 clamp(52px,7vw,92px);
  position:relative;overflow:hidden;
}
.hero::before{
  /* a single soft light source behind the answer panel, not an ambient blob party */
  content:"";position:absolute;top:-14%;right:-6%;width:52%;aspect-ratio:1;
  background:radial-gradient(circle,rgba(59,130,246,.16) 0%,rgba(34,211,238,.05) 42%,transparent 68%);
  pointer-events:none;
}
.hero .wrap{position:relative;display:grid;grid-template-columns:1fr 1fr;gap:clamp(32px,5vw,68px);align-items:center}
.hero h1{margin-bottom:.34em}
.hero .lede{color:var(--mute);max-width:30em}

/* The figure column is laid out here rather than inline, so the media queries
   below can actually win. An inline style beats a stylesheet rule and the
   mobile override was silently doing nothing. */
.hero-fig{display:flex;gap:22px;align-items:flex-end;justify-content:flex-end;flex-wrap:wrap}
.hero-fig .answer{flex:1 1 320px;min-width:0}

@media(max-width:900px){
  /* The headline and the credential lead on a phone. Putting the illustration
     first pushed both below the fold, which is the wrong trade on the page
     that has to sell the book. */
  .hero .wrap{grid-template-columns:1fr}
  .hero-fig{justify-content:flex-start;align-items:flex-start;margin-top:10px}
  .hero-fig .cover{--w:118px}
}
@media(max-width:560px){
  .hero-fig{flex-direction:column-reverse;align-items:flex-start}
  .hero-fig .cover{--w:104px;margin:0 0 22px}
}

/* ---------- the signature: AI answer panel -------------------------------- */

.answer{
  background:var(--panel);
  border:1px solid var(--line-2);
  border-radius:var(--r);
  padding:20px;
  box-shadow:0 28px 70px -30px rgba(0,0,0,.95);
}
.answer-head{
  display:flex;align-items:center;gap:8px;
  font-family:var(--mono);font-size:.66rem;letter-spacing:.16em;text-transform:uppercase;
  color:var(--mute-2);padding-bottom:14px;margin-bottom:6px;border-bottom:1px solid var(--line);
}
.answer-head .dot{width:6px;height:6px;border-radius:50%;background:var(--cy);flex:none}
.answer-q{
  font-family:var(--body);font-size:.98rem;color:var(--mute);
  margin:12px 0 16px;max-width:none;font-style:italic;
}
.answer-row{
  display:flex;align-items:flex-start;gap:12px;
  padding:13px 14px;border-radius:10px;margin-bottom:8px;
  border:1px solid transparent;
}
.answer-row .mark{
  flex:none;width:22px;height:22px;border-radius:50%;
  border:1.5px solid var(--line-2);margin-top:1px;
  display:grid;place-items:center;
}
.answer-row .rname{font-family:var(--display);font-weight:700;font-size:1rem;color:var(--paper);letter-spacing:-.01em}
.answer-row .rdesc{font-size:.88rem;color:var(--mute);line-height:1.5}
.answer-row.is-you{
  background:linear-gradient(96deg,rgba(34,211,238,.13),rgba(59,130,246,.13));
  border-color:rgba(59,130,246,.45);
}
.answer-row.is-you .mark{border-color:transparent;background:var(--grad)}
.answer-row.is-you .rname{color:var(--paper-hi)}
.answer-row.is-you .rdesc{color:#B9C9DC}
.answer-row.is-them{opacity:.6}
.answer-foot{
  font-family:var(--mono);font-size:.66rem;letter-spacing:.1em;text-transform:uppercase;
  color:var(--mute-2);padding-top:13px;margin-top:6px;border-top:1px solid var(--line);
}

/* one orchestrated load sequence, nothing else moves */
.answer-row{opacity:0;transform:translateY(7px);animation:settle .5s cubic-bezier(.2,.7,.2,1) forwards}
.answer-row.is-them{animation-name:settle-dim}
.answer-row:nth-child(1){animation-delay:.34s}
.answer-row:nth-child(2){animation-delay:.50s}
.answer-row:nth-child(3){animation-delay:.62s}
.answer-q{opacity:0;animation:settle .45s ease forwards .1s}
@keyframes settle{to{opacity:1;transform:none}}
@keyframes settle-dim{to{opacity:.6;transform:none}}

@media(prefers-reduced-motion:reduce){
  .answer-row,.answer-q{animation:none;opacity:1;transform:none}
  .answer-row.is-them{opacity:.6}
  *{scroll-behavior:auto !important}
}

/* ---------- book cover ---------------------------------------------------- */

.cover{
  --w:200px;--t:calc(var(--w)*.104);--h:calc(var(--w)*1.55);
  width:var(--w);height:var(--h);perspective:1600px;position:relative;flex:none;
}
.cover-i{
  position:relative;width:100%;height:100%;transform-style:preserve-3d;
  transform:rotateY(24deg);transition:transform .7s cubic-bezier(.2,.7,.2,1);
}
.cover:hover .cover-i{transform:rotateY(14deg) translateY(-5px)}
@media(prefers-reduced-motion:reduce){.cover:hover .cover-i{transform:rotateY(24deg)}}
.cover-face{position:absolute;inset:0;backface-visibility:hidden}
.cover-front{
  transform:translateZ(calc(var(--t)/2));border-radius:1px 3px 3px 1px;overflow:hidden;
  box-shadow:0 0 0 1px rgba(255,255,255,.09);
}
.cover-front img{width:100%;height:100%;object-fit:cover}
.cover-front::after{
  content:"";position:absolute;inset:0;pointer-events:none;
  background:linear-gradient(90deg,rgba(0,0,0,.45) 0,rgba(0,0,0,.14) 1.4%,transparent 3.6%,transparent 90%,rgba(255,255,255,.06) 100%);
}
.cover-spine{
  width:var(--t);left:calc(var(--t)/-2);transform:rotateY(-90deg);
  background:linear-gradient(90deg,#04060A 0,#141A22 40%,#171E27 66%,#04060A 100%);
}
.cover::after{
  content:"";position:absolute;left:3%;right:-5%;bottom:-16px;height:24px;
  background:radial-gradient(ellipse at 50% 50%,rgba(0,0,0,.7) 0,rgba(0,0,0,.25) 45%,transparent 72%);
  filter:blur(9px);
}

/* ---------- readout bar (instrument, not a stat grid) --------------------- */

.readout{
  border-block:1px solid var(--line);background:var(--ink-2);
  padding:22px 0;
}
.readout .wrap{
  display:grid;grid-template-columns:repeat(auto-fit,minmax(210px,1fr));
}
.readout .cell{padding:14px 26px;border-left:1px solid var(--line)}
.readout .cell:first-child{border-left:0;padding-left:0}
.readout .k{
  font-family:var(--mono);font-size:.64rem;letter-spacing:.15em;text-transform:uppercase;
  color:var(--mute-2);display:block;margin-bottom:6px;
}
.readout .v{
  font-family:var(--display);font-weight:800;font-size:1.6rem;letter-spacing:-.03em;
  color:var(--paper-hi);font-variant-numeric:tabular-nums;display:block;line-height:1.1;
}
.readout .n{font-size:.8rem;color:var(--mute);display:block;margin-top:4px;line-height:1.45;font-family:var(--body)}
@media(max-width:640px){.readout .wrap{grid-template-columns:1fr}}

/* ---------- parts list (a real sequence, so it is numbered) --------------- */

.parts{list-style:none;margin:0;padding:0;counter-reset:pt}
.parts li{
  counter-increment:pt;
  display:grid;grid-template-columns:auto 1fr;gap:20px;
  padding:22px 0;border-top:1px solid var(--line);
}
.parts li::before{
  content:"PART " counter(pt);
  font-family:var(--mono);font-size:.66rem;letter-spacing:.13em;color:var(--mute-2);
  padding-top:.45em;white-space:nowrap;
}
.parts h3{margin:0 0 .3em}
.parts p{margin:0;color:var(--mute);font-size:.98rem;max-width:46em}

/* ---------- chapters ------------------------------------------------------ */

.part-block{margin:0 0 52px}
.part-title{
  display:flex;align-items:baseline;gap:14px;
  padding-bottom:12px;margin-bottom:4px;border-bottom:1px solid var(--line-2);
}
.part-title .pn{
  font-family:var(--mono);font-size:.68rem;letter-spacing:.14em;color:var(--cy);
  text-transform:uppercase;flex:none;
}
.part-title h2{margin:0;font-size:clamp(1.4rem,2.6vw,1.9rem)}
.chapters{list-style:none;margin:0;padding:0}
.chapters li{display:grid;grid-template-columns:auto 1fr;gap:18px;padding:16px 0;border-bottom:1px solid var(--line)}
.chapters .cn{font-family:var(--mono);font-size:.8rem;color:var(--mute-2);padding-top:.15em;font-variant-numeric:tabular-nums}
.chapters h3{margin:0 0 .22em;font-size:1.04rem;font-weight:700}
.chapters p{margin:0;font-size:.94rem;color:var(--mute);max-width:48em;line-height:1.62}

/* ---------- cards --------------------------------------------------------- */

.cards{display:grid;grid-template-columns:repeat(auto-fit,minmax(268px,1fr));gap:1px;background:var(--line);border:1px solid var(--line);border-radius:var(--r);overflow:hidden}
/* A set of four auto-fits to three columns at desktop width and leaves a
   two-column hole on the second row. Four is a 2x2. */
.cards--2{grid-template-columns:repeat(2,minmax(0,1fr))}
@media(max-width:720px){.cards--2{grid-template-columns:1fr}}
.cards .card{background:var(--ink-2);padding:26px 24px}
.cards .card h3{margin:0 0 .45em}
.cards .card p{margin:0;color:var(--mute);font-size:.96rem;max-width:none}
.cards .card .eyebrow{margin-bottom:.9rem}

/* ---------- reviews ------------------------------------------------------- */

.stars{color:var(--gold);display:inline-flex;gap:2px;line-height:1;vertical-align:-1px}
.rating-line{
  display:inline-flex;align-items:center;gap:.55em;flex-wrap:wrap;
  font-family:var(--mono);font-size:.78rem;letter-spacing:.04em;color:var(--mute);
}
.rating-line b{color:var(--paper-hi);font-family:var(--display);font-size:.95rem;letter-spacing:-.01em}

.reviews{display:grid;grid-template-columns:repeat(auto-fit,minmax(260px,1fr));gap:18px;margin:1.8em 0 0}
.review{
  background:var(--panel);border:1px solid var(--line);border-radius:var(--r);
  padding:22px 22px 20px;display:flex;flex-direction:column;gap:10px;
}
.review .stars{font-size:0}
.review h3{font-size:1rem;margin:0;line-height:1.32}
.review p{margin:0;font-size:.95rem;line-height:1.62;color:var(--paper);max-width:none}
.review footer{
  margin-top:auto;padding-top:12px;border-top:1px solid var(--line);
  font-family:var(--mono);font-size:.7rem;letter-spacing:.05em;color:var(--mute-2);
}
.review footer b{color:var(--paper);font-weight:400}

/* ---------- glossary ------------------------------------------------------ */

.terms{margin:0;padding:0}
.term{padding:26px 0;border-top:1px solid var(--line)}
.term:target{background:rgba(34,211,238,.05);border-radius:8px;padding-inline:16px;margin-inline:-16px}
.term dt{
  font-family:var(--display);font-weight:800;font-size:1.12rem;color:var(--paper-hi);
  letter-spacing:-.015em;margin:0 0 .4em;
}
.term dd{margin:0;color:var(--paper);font-size:1rem;line-height:1.7}
.term dd p{max-width:46em}
.term dd p:last-child{margin-bottom:0}

.jump{
  display:flex;flex-wrap:wrap;gap:6px;margin:0 0 8px;padding:0;list-style:none;
}
.jump a{
  font-family:var(--mono);font-size:.74rem;color:var(--mute);text-decoration:none;
  border:1px solid var(--line-2);border-radius:7px;padding:5px 10px;display:block;
}
.jump a:hover{color:var(--paper-hi);border-color:var(--cy)}

/* ---------- forms --------------------------------------------------------- */

.capture{
  background:var(--panel);border:1px solid var(--line-2);border-radius:var(--r);
  padding:clamp(24px,4vw,36px);
}
.field{display:flex;gap:10px;flex-wrap:wrap;margin:0 0 12px}
.field input{
  flex:1;min-width:220px;background:var(--ink);border:1px solid var(--line-2);
  color:var(--paper);font-family:var(--body);font-size:1rem;
  padding:14px 16px;border-radius:10px;
}
.field input::placeholder{color:var(--mute-2)}
.field input:focus{border-color:var(--cy);outline:none}
.form-note{font-size:.84rem;color:var(--mute-2);margin:0;max-width:44em}
.form-msg{font-family:var(--mono);font-size:.82rem;margin:12px 0 0;min-height:1.2em}
.form-msg[data-state=ok]{color:var(--cy)}
.form-msg[data-state=err]{color:#FF9B8A}

/* ---------- tables -------------------------------------------------------- */

.tbl-wrap{overflow-x:auto;border:1px solid var(--line);border-radius:var(--r)}
table{border-collapse:collapse;width:100%;font-size:.95rem;min-width:520px}
th,td{text-align:left;padding:14px 18px;border-bottom:1px solid var(--line);vertical-align:top}
th{
  font-family:var(--mono);font-size:.66rem;letter-spacing:.13em;text-transform:uppercase;
  color:var(--mute-2);font-weight:400;background:var(--ink-2);
}
tr:last-child td{border-bottom:0}
td strong{font-family:var(--display);font-weight:700}

/* ---------- two-column editorial block ------------------------------------ */

.split{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1.25fr);gap:clamp(28px,5vw,72px);align-items:start}
.split .split-head{position:sticky;top:96px}
.split h2{margin-bottom:.4em}
.split p{max-width:38em}
@media(max-width:820px){
  .split{grid-template-columns:1fr;gap:22px}
  .split .split-head{position:static}
}

/* ---------- prose lists --------------------------------------------------- */

.prose ul,.prose ol{max-width:var(--measure);padding-left:1.25em;margin:0 0 1.25em}
.prose li{margin:0 0 .5em}
.prose h2{margin-top:2em}
.prose h3{margin-top:1.7em}
.prose h2:first-child,.prose h3:first-child{margin-top:0}

blockquote{
  margin:0 0 1.4em;padding:2px 0 2px 22px;border-left:2px solid var(--cy);
  font-size:1.08rem;line-height:1.66;color:var(--paper);
}
blockquote cite{
  display:block;font-family:var(--mono);font-size:.74rem;font-style:normal;
  letter-spacing:.08em;text-transform:uppercase;color:var(--mute-2);margin-top:.7em;
}

code{font-family:var(--mono);font-size:.88em;background:var(--panel);border:1px solid var(--line);border-radius:5px;padding:.1em .38em}

/* ---------- footer -------------------------------------------------------- */

.site-foot{border-top:1px solid var(--line);padding:52px 0 40px;background:var(--ink-2)}
.foot-grid{display:grid;grid-template-columns:1.4fr 1fr 1fr;gap:36px}
.foot-grid h4{
  font-family:var(--mono);font-size:.66rem;letter-spacing:.15em;text-transform:uppercase;
  color:var(--mute-2);font-weight:400;margin:0 0 14px;
}
.foot-grid ul{list-style:none;margin:0;padding:0}
.foot-grid li{margin:0 0 9px}
.foot-grid a{color:var(--mute);text-decoration:none;font-size:.94rem}
.foot-grid a:hover{color:var(--paper-hi)}
.foot-note{margin:36px 0 0;padding-top:22px;border-top:1px solid var(--line);color:var(--mute-2);font-size:.84rem;max-width:none}
.foot-note a{color:var(--mute)}
@media(max-width:760px){.foot-grid{grid-template-columns:1fr;gap:28px}}

/* ---------- utility ------------------------------------------------------- */

.center{text-align:center}
.center p{margin-inline:auto}
.vh{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}
.mt0{margin-top:0}
.stack>*+*{margin-top:1.1em}
.source{font-family:var(--mono);font-size:.72rem;color:var(--mute-2);letter-spacing:.02em;max-width:52em}
.source a{color:var(--mute)}